/extra/project-euler/020/020.factor

http://github.com/abeaumont/factor · Factor · 25 lines · 5 code · 9 blank · 11 comment · 0 complexity · 88fecd320dbbffb780a061c9d7d48d84 MD5 · raw file

  1. ! Copyright (c) 2007, 2008 Aaron Schaefer.
  2. ! See http://factorcode.org/license.txt for BSD license.
  3. USING: math.combinatorics project-euler.common sequences ;
  4. IN: project-euler.020
  5. ! http://projecteuler.net/index.php?section=problems&id=20
  6. ! DESCRIPTION
  7. ! -----------
  8. ! n! means n * (n - 1) * ... * 3 * 2 * 1
  9. ! Find the sum of the digits in the number 100!
  10. ! SOLUTION
  11. ! --------
  12. : euler020 ( -- answer )
  13. 100 factorial number>digits sum ;
  14. ! [ euler020 ] 100 ave-time
  15. ! 0 ms ave run time - 0.55 (100 trials)
  16. SOLUTION: euler020